The present invention concerns the treatment of particulate interpolymers of ethylene having pendant carboxyl groups.
Particles of ethylene interpolymers having pendant carboxyl groups tend to stick together or cohere during storage, particularly in a warm environment. This is particularly present when the amount of monomer or monomers containing the carboxyl group is present in the polymer in amounts of 10% by weight and above. These polymers tend to bridge together in handling systems, during shipping, storage, and in fabricating equipment lines due to the tendency to stick and block, particularly when such polymers are in the form of pellets or chips. This results in an economic loss, in terms of slow downs, to physically unblock the storage bins and sometimes in shutdowns of production lines.
G. R. Looney et al. in U.S. Pat. No. 3,753,965 discloses a method for deblocking particles of the polymers containing ethylene and acrylic acid by treating such polymers in a solution of a base material.
It may be desirable to perform the treatment step simultaneously while chopping strands of the polymer into pellets or the like.
The present invention provides alternate treatment solutions which, in some instances, are superior to those employed by Looney. Also, the treatment solutions of the present invention do not, in most instances, significantly adversely affect the physical properties of the polymer.